1. Field of the Invention
The present invention relates to a portable chamfering machine capable of chamfering the edge or arris portion of a material to be machined along its outer circumference, and which is also capable of chamfering edge or arris portions of holes or grooves in the material, along inner circumferences of these holes or grooves.
2. Description of the Related Art
A well-known portable chamfering machine for chamfering the edge or arris portion of a material by means of a rotating cutter made up of a series of cutting blades and mounted at the front end thereof is provided with guide faces arranged perpendicular to each other and placed on the edge or arris portion of the material and a guide is provided to expose the cutting blades of the rotating cutter tilted from the guide faces. In the case of this chamfering machine, chamfering is conducted by moving the chamfering machine along the edge or arris portion of the material while keeping the perpendicularly-crossing guide faces of the guide positioned on the edge or arris portion.
In the case of this conventional portable chamfering machine, however, the perpendicularly-crossing guide faces of the guide located adjacent to the rotating cutter constitute an obstacle, as they prevent the chamfering machine from moving smoothly along the inner face of a hole when the edge or arris portion of the hole is to be chamfered, thus reducing the chamfering efficiency.
The author of the present invention has therefore provided in preliminarily-opened Japanese Utility Model Application Sho 63-114293 a chamfering machine including a guide base attached to one end of a housing in which a motor is housed, a rotating shaft projecting from the guide base, a cutting blade fixed to the rotating shaft and projecting from the guide base, and a guide attached to that portion of the rotating shaft below the level at which the cutting blade is attached, and placed in contact with the inner face of a hole formed in a material to be chamfered, or with the curved side of the material. This chamfering machine performs the chamfering of holes and curved sides of a material by being moved with the guide base mounted on a plane face of the material, and the guide thus in contact with the inner face the hole or curved side of the material.
This chamfering machine undoubtedly solves the problem of how to enhance the efficiency of the chamfering process. To further improve the capabilities of the chamfering machine, however, it must also have systems for easily adjusting the amount of material chamfered and enabling a used cutter to be easily replaced by a new one.